Why am I unable to view the coefficients of my arbitrary group delay filter in the FDATOOL GUI using Signal Processing Toolbox 6.2.1 (R14SP1)?

When I do the following:

1. Start a new MATLAB session

2. Launch the FDATOOL GUI by entering "fdatool" at the MATLAB command prompt.

3. Change "Differentiator" to "Arbitrary Group Delay" under Response type.

4. Click the button that reads "Design Filter" to design the filter with the default settings.

5. Click the "[b,a]" button in the toolbar to view the filter coefficients.

I receive the following error:

 ??? Undefined variable "strcell" or class "strcell".

 Warning: Error occurred while evaluating listener callback.

 > In siggui.fvtool.listeners>analysis_listener at 35

   In siggui.fvtool.listeners at 8

   In siggui.fvtool.callbacks>analysis_cb at 28

Also, the FDATOOL GUI hangs while stating "Computing Response..." is at the bottom showing its status.

Answer 1

[MathWorks Support Team]

This bug has been fixed in Release 14 Service Pack 2 (R14SP2). For previous releases, please read below for any possible workarounds:

We have verified that there is a bug in Signal Processing Toolbox 6.2.1 (R14SP1) in the way that FVTOOL handles viewing the coefficients of Arbitrary Group Delay filters. FDATOOL uses an integrated version of FVTOOL to allow you to analyze the filters you have designed. The "[b,a]" item in the FDATOOL toolbar is one of these integrated tools.

To work around this issue, export the filter coefficients to the workspace to view their values.